Observation of ultrafast free carrier dynamics in single layer MoS2

Antonija Cabo; Jill Miwa; Signe Grønborg; Jonathon Mark Riley; Jens Johannsen; Cephise Cacho; Oliver Alexander; Richard Chapman; Emma Springate; Marco Grioni; Jeppe Lauritsen; Phil King; Philip Hofmann; Søren Ulstrup

doi:10.1021/acs.nanolett.5b01967

Observation of ultrafast free carrier dynamics in single layer MoS₂

Antonija Cabo, Jill Miwa, Signe Grønborg, Jonathon Mark Riley, Jens Johannsen, Cephise Cacho, Oliver Alexander, Richard Chapman, Emma Springate, Marco Grioni, Jeppe Lauritsen, Phil King, Philip Hofmann, Søren Ulstrup

Research output: Contribution to journal › Letter › peer-review

Abstract

The dynamics of excited electrons and holes in single layer (SL) MoS₂ have so far been difficult to disentangle from the excitons that dominate the optical response of this material. Here, we use time- and angle-resolved photoemission spectroscopy for an SL of MoS₂ on a metallic substrate to directly measure the excited free carriers. This allows us to ascertain a direct quasiparticle band gap of 1.95 eV and determine an ultrafast (50 fs) extraction of excited free carriers via the metal in contact with the SL MoS₂. This process is of key importance for optoelectronic applications that rely on separated free carriers rather than excitons.

Original language	English
Pages (from-to)	5883–5887
Journal	Nano Letters
Volume	15
Issue number	9
Early online date	19 Aug 2015
DOIs	https://doi.org/10.1021/acs.nanolett.5b01967
Publication status	Published - 9 Sept 2015

Keywords

Transition metal dichalcogenides
MoS2
Free carriers
Exitons
Time- and angle-resolved photoemission spectroscopy

Access to Document

10.1021/acs.nanolett.5b01967

King_2015_NL_Observation_AM
Copyright © 2015 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Nano Letters, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see [insert ACS Articles on Request author-directed link to Published Work, see https://dx.doi.org/10.1021/acs.nanolett.5b01967
Accepted author manuscript, 713 KB

Royal Society Research Fellowship: Electronic structure engineering of novel topological phases
King, P. (PI)
The Royal Society
1/10/13 → 30/09/18
Project: Fellowship
Genetic markers for flesh quality: Genetic markers for flesh quality in farmed fish
Johnston, I. A. (PI)
BBSRC
1/02/12 → 31/01/13
Project: Standard
Topological Protection and NonEquilibriu: Topological Protection and NonEquilibrium States in Strongly Correlated Electron Systems
Wahl, P. (PI), Baumberger, F. (CoI), Davis, J. C. (CoI), Green, A. (CoI), Hooley, C. (CoI), Keeling, J. M. J. (CoI) & Mackenzie, A. (CoI)
EPSRC
1/09/11 → 31/08/17
Project: Standard

Underpinning data : Observation of Ultrafast Free Carrier Dynamics in Single Layer MoS2
Cabo, A. (Creator), Miwa, J. (Creator), Grønborg, S. (Creator), Riley, J. M. (Creator), Johannsen, J. (Creator), Cacho, C. (Creator), Alexander, O. (Creator), Chapman, R. (Creator), Springate, E. (Creator), Grioni, M. (Creator), Lauritsen, J. (Creator), King, P. D. (Creator), Hofmann, P. (Creator) & Ulstrup, S. (Creator), University of St Andrews, 2015
DOI: 10.17630/35bf1069-6ed4-4b08-9eca-0bf5483ad753
Dataset

File

Cite this

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title = "Observation of ultrafast free carrier dynamics in single layer MoS2",

abstract = "The dynamics of excited electrons and holes in single layer (SL) MoS2 have so far been difficult to disentangle from the excitons that dominate the optical response of this material. Here, we use time- and angle-resolved photoemission spectroscopy for an SL of MoS2 on a metallic substrate to directly measure the excited free carriers. This allows us to ascertain a direct quasiparticle band gap of 1.95 eV and determine an ultrafast (50 fs) extraction of excited free carriers via the metal in contact with the SL MoS2. This process is of key importance for optoelectronic applications that rely on separated free carriers rather than excitons.",

keywords = "Transition metal dichalcogenides, MoS2, Free carriers, Exitons, Time- and angle-resolved photoemission spectroscopy",

author = "Antonija Cabo and Jill Miwa and Signe Gr{\o}nborg and Riley, {Jonathon Mark} and Jens Johannsen and Cephise Cacho and Oliver Alexander and Richard Chapman and Emma Springate and Marco Grioni and Jeppe Lauritsen and Phil King and Philip Hofmann and S{\o}ren Ulstrup",

note = "The authors gratefully acknowledge funding from the VILLUM foundation, the Lundbeck foundation, Haldor Tops{\o}e A/S, the Danish Strategic Research Council (CAT-C), EPSRC (Grant Nos. EP/I031014/1 and EP/L505079/1), The Royal Society, and the Swiss National Science Foundation (NSF). Ph.H. and S.U. acknowledge financial support from the Danish Council for Independent Research, Natural Sciences under the Sapere Aude program (Grant Nos. DFF-4002-00029 and DFF-4090-00125). Date of Accepted 19/08/2015",

year = "2015",

month = sep,

day = "9",

doi = "10.1021/acs.nanolett.5b01967",

language = "English",

volume = "15",

pages = "5883–5887",

journal = "Nano Letters",

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T1 - Observation of ultrafast free carrier dynamics in single layer MoS2

AU - Cabo, Antonija

AU - Miwa, Jill

AU - Grønborg, Signe

AU - Riley, Jonathon Mark

AU - Johannsen, Jens

AU - Cacho, Cephise

AU - Alexander, Oliver

AU - Chapman, Richard

AU - Springate, Emma

AU - Grioni, Marco

AU - Lauritsen, Jeppe

AU - King, Phil

AU - Hofmann, Philip

AU - Ulstrup, Søren

N1 - The authors gratefully acknowledge funding from the VILLUM foundation, the Lundbeck foundation, Haldor Topsøe A/S, the Danish Strategic Research Council (CAT-C), EPSRC (Grant Nos. EP/I031014/1 and EP/L505079/1), The Royal Society, and the Swiss National Science Foundation (NSF). Ph.H. and S.U. acknowledge financial support from the Danish Council for Independent Research, Natural Sciences under the Sapere Aude program (Grant Nos. DFF-4002-00029 and DFF-4090-00125). Date of Accepted 19/08/2015

PY - 2015/9/9

Y1 - 2015/9/9

N2 - The dynamics of excited electrons and holes in single layer (SL) MoS2 have so far been difficult to disentangle from the excitons that dominate the optical response of this material. Here, we use time- and angle-resolved photoemission spectroscopy for an SL of MoS2 on a metallic substrate to directly measure the excited free carriers. This allows us to ascertain a direct quasiparticle band gap of 1.95 eV and determine an ultrafast (50 fs) extraction of excited free carriers via the metal in contact with the SL MoS2. This process is of key importance for optoelectronic applications that rely on separated free carriers rather than excitons.

AB - The dynamics of excited electrons and holes in single layer (SL) MoS2 have so far been difficult to disentangle from the excitons that dominate the optical response of this material. Here, we use time- and angle-resolved photoemission spectroscopy for an SL of MoS2 on a metallic substrate to directly measure the excited free carriers. This allows us to ascertain a direct quasiparticle band gap of 1.95 eV and determine an ultrafast (50 fs) extraction of excited free carriers via the metal in contact with the SL MoS2. This process is of key importance for optoelectronic applications that rely on separated free carriers rather than excitons.

KW - Transition metal dichalcogenides

KW - MoS2

KW - Free carriers

KW - Exitons

KW - Time- and angle-resolved photoemission spectroscopy

U2 - 10.1021/acs.nanolett.5b01967

DO - 10.1021/acs.nanolett.5b01967

M3 - Letter

SN - 1530-6984

VL - 15

SP - 5883

EP - 5887

JO - Nano Letters

JF - Nano Letters

IS - 9

ER -

Observation of ultrafast free carrier dynamics in single layer MoS2

Abstract

Keywords

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Projects

Royal Society Research Fellowship: Electronic structure engineering of novel topological phases

Genetic markers for flesh quality: Genetic markers for flesh quality in farmed fish

Topological Protection and NonEquilibriu: Topological Protection and NonEquilibrium States in Strongly Correlated Electron Systems

Datasets

Underpinning data : Observation of Ultrafast Free Carrier Dynamics in Single Layer MoS2

Cite this

Observation of ultrafast free carrier dynamics in single layer MoS₂